Modern wireless and wireline communications systems provide various types of services to customers, including normal calling, paging, messaging, internet access, etc., where the customer (sometimes referred to as a subscriber) is able to select from a wide range of calling plans for today's mobile phone. Most plans are either post-paid, in which services are provided in a given time period, with the customer being billed at the end of the billing period, or pre-paid type plans in which the customer must pay in advance to ensure communications services are available when subsequently needed. Service providers currently offer a number of calling plans designed to allow subscribers to select the types of services that will be available when using their mobile phone or phones. Most post-paid service plans offer either limited anytime minute plans, for instance, in which the subscriber may use 300, 500, 700, 1,000 minutes at a favorable price within a given billing period, typically a month, as well as unlimited plans. For post-paid plans offering limited anytime minutes, the subscriber can use up to the stated limit at a first rate (often included in a flat rate monthly base charge), after which further minutes are charged at a higher rate, with the bill reflecting any charges for exceeding the minutes limit. For pre-paid plans, the user can make calls until the account balance reaches zero, after which the phone will not work until the subscriber replenishes the account.
Shared subscriber plans or family plans are becoming popular, in which post-paid services are provided for a number of phones, with the costs being billed together. Such plans are typically directed to family groups, friends, small businesses, etc., where the plan holder is allowed to have multiple phones with multiple phone numbers. As with single subscriber plans, the shared subscriber plans may also be provided with unlimited minutes or with a limited number of total anytime minutes for the group as a whole, with overages being reflected on the bill at the end of the month. In many group situations, however, one or a few shared plan members use the majority of the available minutes, with the plan account often incurring excess charges with no control over the overall group usage and no indication of excessive phone use by certain members until the bill is received.